Burnham 805H Installation, Operating And Service Instructions page 29

Table 6: Maximum Capacity of Schedule 40 Pipe in CFH for Gas Pressures of 0.5 psig or Less
Length
(Feet)
½
10 132
20 92
30 73
40 63
50 56
60 50
70 46
80 43
90 40
100 38
Table 7: Equivalent Lengths of Standard Pipe Fittings & Valves
Pipe I.D.
Size (Inches)
½" 0.622
¾" 0.824
1" 1.049
1¼" 1.380
Table 8: Specific Gravity Correction Factors
Specific Correction
Gravity Factor
0.50 1.10
0.55 1.04
0.60 1.00
0.65 0.96
0.70 0.93
0.75 0.90
0.80 0.87
C.
Pressure Test. The boiler and its gas connection must
be leak tested before placing boiler in operation.
1. Protect boiler gas valve. For all testing over ½ psig,
boiler and its individual shut-off valve must be
disconnected from gas supply piping. For testing at
½ psig or less, isolate boiler from gas supply piping
by closing boiler's individual manual shut-off valve.
2. Locate leaks using approved combustible gas
detector, soap and water, or similar nonflammable
solution.
0.3 Inch w.c. Pressure Drop
¾ 1
278 520
190 350
152 285
130 245
115 215
105 195
96 180
90 170
84 160
79 150
Valves (Fully Open)
Gate Globe Angle
0.35 18.6 9.3
0.44 23.1 11.5
0.56 29.4 14.7
0.74 38.6 19.3
Specific Correction
Gravity Factor
1.30 1.07
1.40 1.04
1.50 1.00
1.60 0.97
1.70 0.94
--- ---
--- ---
1¼ ½
1,050 175
730 120
590 97
500 82
440 73
400 66
370 61
350 57
320 53
305 50
Swing 90° 45°
Check Elbow Elbow
4.3 1.6 0.78
5.3 2.1 0.97
6.8 2.6 1.23
8.9 3.5 1.6
Do not use matches, candles, open flames, or
other ignition source.
Figure 22: Recommended Gas Piping
0.5 Inch w.c. Pressure Drop
¾ 1
360 680
250 465
200 375
170 320
151 285
138 260
125 240
118 220
110 205
103 195
Threaded Fittings
90° Tee, Flow
Through Run Through Branch
1.0
1.4
1.8
2.3
1¼
1,400
950
770
660
580
530
490
460
430
400
90° Tee, Flow
3.1
4.1
5.3
6.9
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